Finally, we point out that MATHUSLA is not only a new physics discovery machine, it can also measure the properties of newly discovered particles in great detail.
This was the subject of [1]} (see also [2]}, [3]}), which demonstrate how MATHUSLA can characterize the new physics by working in tandem with the CMS main detector. This allows for determination of LLP decay mode, mass, production mode, and underlying parameters of the new physics theory like the parent particle mass with only \(\mathcal {O}(10 - 100)\)  observed LLP decays.
Unlocking this surprisingly broad analysis capability, given that MATHUSLA does not collect energy or momentum information, requires MATHUSLA to act as a Level-1 Trigger for CMS, allowing for the correlation of information from both detectors.
